A temporary facility is under construction to store radioactive waste (sludge) generated in the processing of radiation-tainted water, at the Fukushima Daiichi nuclear power station operated by Tokyo Electric Power Company Inc. (TEPCO).
The operator is currently taking various measures towards restoration after the facility was severely damaged by last years devastating earthquake and subsequent tsunami.
At present, reactors are being cooled by circulating water that is treated by radioactive substance removal and desalination processes.
The storage facility being constructed will stably store radioactive sludge generated during coagulated settling within the decontamination apparatus in the radioactive substance removal process.
The facility, being built by Mitsubishi Heavy Industries Ltd (MHI), will consist of a number of facilities and systems, including sludge storage tanks to be installed in a cell room surrounded by 1 metre thick concrete walls, a system to process off-gas from the sludge storage tanks, a ventilation and air-conditioning system, a control system, and utility facilities.
According to MHI, the 13.5 metre long, 3.2 metre diameter cylindrical sludge storage tanks will be made of 25 mm thick iron.
Eight tanks, including one for backup, with sludge storage capacities of up to 90 cubic meters each, will be horizontally installed in the facility. The tanks will also function to agitate waste sludge and scavenge hydrogen.
MHI says that it has been involved in a variety of ways with the recovery efforts at the Fukushima Daiichi facility, including conversion of a ‘Mega-Float’ for pooling of moderately radiated accumulated water and the provision of forklift truck-based special vehicles equipped with a radiation-shielded cabin to handle rubble in the accident site.
